The cathodic reaction mechanism of acetic acid corrosion has been systematically investigated using density functional theory (DFT), and the findings were validated through electrochemical experiments and mechanistic modeling. DFT calculations revealed that the adsorption energy of acetic acid on the Fe(110) surface was consistently positive, indicating that the adsorption process is endothermic, followed by dissociation as the dominant pathway. In contrast, dissociated H⁺ exhibited spontaneous exothermic adsorption on Fe(110), and strong charge transfer between H⁺ and Fe confirmed the thermodynamic preference for H⁺ reduction over direct involvement of acetic acid. Electrochemical analyses further demonstrated that acetic acid enhances corrosion primarily through its buffering effect (supplying additional H⁺ via dissociation). Based on the established buffering effect, a corrosion rate prediction model for acetic acid was optimized, and the optimized model showed improved accuracy, confirming that direct reduction of acetic acid should be ignored.

The harsh marine environment causes the corrosion of gusset plates on offshore platforms, which seriously threatens their safety and lifespan. This study investigates the corrosion behavior of 16Mn steel gusset plates in a marine environment, focusing on the effects of chloride ion concentration, dry-wet ratio, and applied stress. The mathematical model, developed using Response Surface Methodology (RSM) and COMSOL Multiphysics simulations, reveals that chloride ion concentration exerts the greatest influence on the corrosion rate, followed by the dry-wet ratio and applied stress. A significant interaction between chloride ion concentration and dry-wet ratio was observed. The model’s R² value is 0.9961, confirming its accuracy. Corrosion mainly occurs at the right-angled edges and curved edges of the gusset plates. These research findings provide a scientific basis for the anti-corrosion design of marine materials, contributing to ensuring the safety of offshore platforms and extending their service life.